Hydrostatic setting tool with degradable-on-demand closure member and method for setting a downhole tool

ABSTRACT

An hydrostatic setting tool including a housing defining a central bore, a piston in the housing, a port in the housing exposed to hydrostatic pressure in use, a closure member preventing access of the hydrostatic pressure to the piston, the closure member comprising a degradable-on-demand material; and a source of energy connected to the closure member. A downhole system including the hydrostatic setting tool. A method for setting a downhole tool.

BACKGROUND

In subsurface resource recovery operations, high temperature and highpressure (HPHT) are often unavoidable conditions that must be endured.There are therefore high pressure and high temperature setting toolsavailable commercially to assist in deployment of tools for thesubsurface environment. Such HPHT tools are effective in achieving theends for which they are employed but many are complicated and require agood deal of length to construct. They also require numerous componentseach of which increases the ultimate price tag for the tool.

The art is always receptive to alternate technologies that reduce lengthand cost of tools while maintaining functional reliability.

SUMMARY

An hydrostatic setting tool including a housing defining a central bore,a piston in the housing, a port in the housing exposed to hydrostaticpressure in use, a closure member preventing access of the hydrostaticpressure to the piston, the closure member comprising adegradable-on-demand material; and a source of energy connected to theclosure member.

A downhole system including the hydrostatic setting tool including ahousing defining a central bore, a piston in the housing, a port in thehousing exposed to hydrostatic pressure in use, a closure memberpreventing access of the hydrostatic pressure to the piston, the closuremember comprising a degradable-on-demand material; and a source ofenergy connected to the closure member.

A method for setting a downhole tool including sending an electricalsignal to a degradable-on-demand closure member of an hydrostaticsetting tool including a housing defining a central bore, a piston inthe housing, a port in the housing exposed to hydrostatic pressure inuse, a closure member preventing access of the hydrostatic pressure tothe piston, the closure member comprising a degradable-on-demandmaterial; and a source of energy connected to the closure member,degrading the closure member; and providing access of hydrostaticpressure to the piston.

BRIEF DESCRIPTION OF THE DRAWINGS

The following descriptions should not be considered limiting in any way.With reference to the accompanying drawings, like elements are numberedalike:

FIG. 1 is a cross sectional view of a first embodiment of an HPHTsetting tool according to the disclosure herein;

FIG. 2 is a cross sectional view of a second embodiment of an HPHTsetting tool according to the disclosure herein;

FIG. 3 is a view of an alternate closure member for the embodiment ofFIG. 2; and

FIG. 4 is a view of another alternate closure member for an embodimentsimilar to FIG. 2.

DETAILED DESCRIPTION

A detailed description of one or more embodiments of the disclosedapparatus and method are presented herein by way of exemplification andnot limitation with reference to the Figures.

Referring to FIG. 1, an HPHT hydrostatic setting tool 10 is illustrated.The setting tool 10 includes a housing 12 having a central bore 14. Thetool includes a piston 16 disposed in the central bore 14, the piston 16bifurcating a portion 18 of the central bore 14 that is maintained atatmospheric or otherwise a lower pressure than hydrostatic pressure at alocation anticipated for use of the setting tool 10. At the other sideof piston 16 is a face 20 that is exposed to a pressure change portion22 of the central bore 14 that portion 22 being maintained apart fromhydrostatic pressure by a set of seals 24 such as o-rings disposed abouta closure member 26 at opposing ends thereof, the member being arrangedin this embodiment substantially in parallel with the central bore 14.The closure member 26 and seals 24 along with seals 28 isolate pressurefrom a port 30 that has direct access to hydrostatic pressure in use bythe closure member bridging the port 30 and placing its seal on eitherside of the port 30. Removal of the closure member 26 from its positionwill allow hydrostatic pressure access to the face 20 of the piston 16resulting in the piston forcefully moving toward the atmospheric orotherwise lower than hydrostatic pressure portion 18 of the central bore14 with attendant energy useful for setting another downhole tool.

The closure member comprises a degradable-on-demand material such asEnergetic material having the structural properties anddegrade-on-demand properties indicated above includes materialcommercially available from Baker Hughes Incorporated, Houston, Tex.Such material is as described below.

The energetic material can be in the form of continuous fibers, wires,foils, particles, pellets, short fibers, or a combination comprising atleast one of the foregoing. In the degradable-on-demand components, theenergetic material is interconnected in such a way that once a reactionof the energetic material is initiated at one or more starting locationsor points, the reaction can self-propagate through the energeticmaterial in the degradable-on-demand components. As used herein,interconnected or interconnection is not limited to physicalinterconnection.

The energetic material comprises a thermite, a thermate, a solidpropellant fuel, or a combination comprising at least one of theforegoing. The thermite materials include a metal powder (a reducingagent) and a metal oxide (an oxidizing agent), where choices for areducing agent include aluminum, magnesium, calcium, titanium, zinc,silicon, boron, and combinations including at least one of theforegoing, for example, while choices for an oxidizing agent includeboron oxide, silicon oxide, chromium oxide, manganese oxide, iron oxide,copper oxide, lead oxide and combinations including at least one of theforegoing, for example.

Thermate materials comprise a metal powder and a salt oxidizer includingnitrate, chromate and perchlorate. For example thermate materialsinclude a combination of barium chromate and zirconium powder; acombination of potassium perchlorate and metal iron powder; acombination of titanium hydride and potassium perchlorate, a combinationof zirconium hydride and potassium perchlorate, a combination of boron,titanium powder, and barium chromate, or a combination of bariumchromate, potassium perchlorate, and tungsten powder.

Solid propellant fuels may be generated from the thermate compositionsby adding a binder that meanwhile serves as a secondary fuel. Thethermate compositions for solid propellants include, but are not limitedto, perchlorate and nitrate, such as ammonium perchlorate, ammoniumnitrate, and potassium nitrate. The binder material is added to form athickened liquid and then cast into various shapes. The binder materialsinclude polybutadiene acrylonitrile (PBAN), hydroxyl-terminatedpolybutadiene (HTPB), or polyurethane. An exemplary solid propellantfuel includes ammonium perchlorate (NH₄ClO₄) grains (20 to 200 μm)embedded in a rubber matrix that contains 69-70% finely ground ammoniumperchlorate (an oxidizer), combined with 16-20% fine aluminum powder (afuel), held together in a base of 11-14% polybutadiene acrylonitrile orhydroxyl-terminated polybutadiene (polybutadiene rubber matrix). Anotherexample of the solid propellant fuels includes zinc metal and sulfurpowder.

The energetic material may also include energetic polymers possessingreactive groups, which are capable of absorbing and dissipating energy.During the activation of energetic polymers, energy absorbed by theenergetic polymers causes the reactive groups on the energetic polymers,such as azido and nitro groups, to decompose releasing gas along withthe dissipation of absorbed energy and/or the dissipation of the energygenerated by the decomposition of the active groups. The heat and gasreleased promote the degradation of the degradation-on-demandcomponents.

Energetic polymers include polymers with azide, nitro, nitrate, nitroso,nitramine, oxetane, triazole, and tetrazole containing groups. Polymersor co-polymers containing other energetic nitrogen containing groups canalso be used. Optionally, the energetic polymers further include fluorogroups such as fluoroalkyl groups.

Exemplary energetic polymers include nitrocellulose, azidocellulose,polysulfide, polyurethane, a fluoropolymer combined with nano particlesof combusting metal fuels, polybutadiene; polyglycidyl nitrate such aspolyGLYN, butanetriol trinitrate, glycidyl azide polymer (GAP), forexample, linear or branched GAP, GAP diol, or GAP triol,poly[3-nitratomethyl-3-methyl oxetane] (polyNIMMO),poly(3,3-bis-(azidomethyl)oxetane (polyBAMO) andpoly(3-azidomethyl-3-methyl oxetane) (polyAMMO), polyvinylnitrate,polynitrophenylene, nitramine polyethers, or a combination comprising atleast one of the foregoing.

The closure member 26 is connected to a source of energy 32 such aselectrical energy from a remote location such as the surface in the formof for example an electric line so that a charge may be applied to theclosure member 26 when it is desired for the closure member to degradethereby allowing the hydrostatic pressure access to face 20 of piston 16to set another tool. Once pressure is allowed to access the face 20, thetool 10 work quite similarly to Baker Hughes Incorporated's commerciallyavailable HPHT hydrostatic pressure setting assembly (product familyH43708). The setting of the other tool (not shown) then is at the whimof the operator who can degrade the degradable-on-demand material atwill by sending an electric signal to the closure member 26. Upon theapplication of the charge to the degradable-on-demand material, thatmaterial is ignited and rapidly degrades leaving the space previouslyoccupied by the closure member open to pressure migration. In thisembodiment, the closure member is entirely formed from thedegradable-on-demand material or it is possible for the material fromthe port to the right thereof in FIG. 1 to be made of thedegradable-on-demand material while the material on the left side of theport may be some other material since all that is necessary for thesetting tool to have effect is for the pressure extant outside of theport 30 (in use) to have access to the face 20 of the piston 16. Theleft side of the closure member 26 may simply be pushed out of the wayin a leftwardly (of FIG. 1) direction.

Because the closure member 26 in the embodiment of FIG. 1 is subjectedto tensile strain when the tool 10 is disposed in an environment withhydrostatic pressure acting thereon through the port 14, since suchpressure will act in both directions from the port 14 to the seals 24and 28, the material will require a tensile strain capability exceedingthe actual tensile strain anticipated to be generated by the tool beingrun to a target depth in a borehole. Fortunately the material discussedabove does indeed possess a high tensile strength and can manage theintended application perfectly.

In an alternate embodiment, referring to FIG. 2, a configuration thatdoes not require significant tensile strength of the material of aclosure member 40 is illustrated. This embodiment puts the closuremember 40 in compression only and hence allows for the use of materialwith a lesser degree of tensile strength, if desired. It will of coursebe understood that the higher tensile strength material is still quitesuitable for this embodiment as well. In this embodiment, the closuremember may be entirely formed from the degradable-on-demand material ormay be configured with a portion of the closure member 40 as anondegradable material while another portion of the closure member is ofthe degradable-on-demand material see FIG. 3.

The housing and operational components of this embodiment are similar tothe foregoing embodiment although for clarity, the port 30 isillustrated with a larger diameter than is shown in FIG. 1. The closuremember 40 comprises seals 42 and 44 that are positioned between externalhydrostatic pressure when in use and the internal pressure of the toolwhich as mentioned above will be atmospheric pressure or otherwise alower than hydrostatic pressure. It will be appreciated that the closuremember 40 as configured in FIG. 2 will act as a piston itself as theseals hold a differential pressure thereacross but it will also be notedthat the closure member 40 extends to an opposing wall of the housing 12and hence the closure member 40 cannot be forced inwardly under theinsistence of the hydrostatic pressure when in use. As in the previousembodiment the closure member is connected to a source of energy 32 suchas electrical energy from a remote location such as the surface in theform of for example an electric line so that a charge may be applied tothe closure member 40 when it is desired for the closure member todegrade thereby allowing the hydrostatic pressure access to face 20 ofpiston 16 to set another tool. Upon the application of the charge to thedegradable-on-demand material, that material is ignited and rapidlydegrades leaving the space previously occupied by the closure memberopen to pressure migration. In some embodiments a retainer 34 such as asnap ring, threaded ring, fastener, etc. may be included to prevent theclosure member 40 falling out of the housing 12 accidentally prior tothe tool 10 experiencing a higher hydrostatic pressure than pressureinternal to the tool 10.

Referring to FIG. 3, the closure member 40 comprises portion 40 a andportion 40 b. The portion 40 a is composed of nondegradable material andthe portion 40 b is of the degradable-on-demand material. Upon ignitionthe portion 40 b is degraded and because that portion of the closuremember 40 is the reason the hydrostatic pressure through port 30 couldnot push the portion 40 a into the housing, the loss of the portion 40 bwill be immediately followed by the hydrostatic pressure forcing theportion 40 a out of the port and into the central bore 14 of the housing12 thereby allowing hydrostatic pressure to contact face 20 of piston16.

Referring to FIG. 4, an alternate degradable-on-demand closure member 50is illustrated in a housing 52 that is slightly altered from the othersillustrated herein. The housing presents a port 54 structure that isstepped. There is a first dimension opening 56 and a second dimensionopening 58 wherein the second dimension opening is radially inwardlylocated relative to an axis 60 of the housing 52. The result is that theclosure member 50 will fit into the first dimension opening 56 and besealed thereto with a seal 62 while physically contacting a stop surface64 occasioned by the existence of the second dimension opening 58. Theclosure member in this position will resist hydrostatic pressure when inuse and does not need to be configured to extend to the wall of thehousing as in the FIG. 2 embodiment discussed above to prevent theclosure member acting as a piston and opening prematurely.

Upon selection, the operator may degrade the degradable-on-demandclosure member 50 on-demand as in the previous embodiments by thedelivery of a signal through line 66.

Set forth below are some embodiments of the foregoing disclosure:

Embodiment 1

An hydrostatic setting tool including a housing defining a central bore,a piston in the housing, a port in the housing exposed to hydrostaticpressure in use, a closure member preventing access of the hydrostaticpressure to the piston, the closure member comprising adegradable-on-demand material; and a source of energy connected to theclosure member.

Embodiment 2

The tool as claimed in any prior embodiment wherein the closure memberis composed entirely of degradable-on-demand material.

Embodiment 3

The tool as claimed in any prior embodiment wherein the closure memberincludes seals at opposing ends, the closure member bridging the port.

Embodiment 4

The tool as claimed in any prior embodiment wherein the closure memberis oriented in parallel with the central bore.

Embodiment 5

The tool as claimed in any prior embodiment wherein the closure memberbears a tensile load.

Embodiment 6

The tool as claimed in any prior embodiment wherein the closure memberis arranged in parallel to the port and substantially perpendicular tothe central bore.

Embodiment 7

The tool as claimed in any prior embodiment wherein the port is stepped.

Embodiment 8

The tool as claimed in any prior embodiment wherein the closure membercontacts a stop surface of the port.

Embodiment 9

The tool as claimed in any prior embodiment wherein the closure memberextends into contact with a wall of the housing preventing differentialpressure based movement of the closure member.

Embodiment 10

The tool as claimed in any prior embodiment wherein the tool furtherincludes a retainer.

Embodiment 11

A downhole system including the hydrostatic setting tool including ahousing defining a central bore, a piston in the housing, a port in thehousing exposed to hydrostatic pressure in use, a closure memberpreventing access of the hydrostatic pressure to the piston, the closuremember comprising a degradable-on-demand material; and a source ofenergy connected to the closure member.

Embodiment 12

A method for setting a downhole tool including sending an electricalsignal to a degradable-on-demand closure member of an hydrostaticsetting tool including a housing defining a central bore, a piston inthe housing, a port in the housing exposed to hydrostatic pressure inuse, a closure member preventing access of the hydrostatic pressure tothe piston, the closure member comprising a degradable-on-demandmaterial; and a source of energy connected to the closure member,degrading the closure member; and providing access of hydrostaticpressure to the piston.

Embodiment 13

The method as claimed in any prior embodiment wherein the degrading isof the entirety of the closure member.

Embodiment 14

The method as claimed in any prior embodiment wherein the degrading isof a portion of the closure member.

Embodiment 15

The method as claimed in any prior embodiment wherein the degradingincludes sending a signal to the closure member.

Embodiment 16

The method as claimed in any prior embodiment wherein the signal iselectrical.

Embodiment 17

The method as claimed in any prior embodiment wherein the degradingincludes igniting of the degradable-on-demand material.

The use of the terms “a” and “an” and “the” and similar referents in thecontext of describing the invention (especially in the context of thefollowing claims) are to be construed to cover both the singular and theplural, unless otherwise indicated herein or clearly contradicted bycontext. Further, it should further be noted that the terms “first,”“second,” and the like herein do not denote any order, quantity, orimportance, but rather are used to distinguish one element from another.The modifier “about” used in connection with a quantity is inclusive ofthe stated value and has the meaning dictated by the context (e.g., itincludes the degree of error associated with measurement of theparticular quantity).

The teachings of the present disclosure may be used in a variety of welloperations. These operations may involve using one or more treatmentagents to treat a formation, the fluids resident in a formation, awellbore, and/or equipment in the wellbore, such as production tubing.The treatment agents may be in the form of liquids, gases, solids,semi-solids, and mixtures thereof. Illustrative treatment agentsinclude, but are not limited to, fracturing fluids, acids, steam, water,brine, anti-corrosion agents, cement, permeability modifiers, drillingmuds, emulsifiers, demulsifiers, tracers, flow improvers etc.Illustrative well operations include, but are not limited to, hydraulicfracturing, stimulation, tracer injection, cleaning, acidizing, steaminjection, water flooding, cementing, etc.

While the invention has been described with reference to an exemplaryembodiment or embodiments, it will be understood by those skilled in theart that various changes may be made and equivalents may be substitutedfor elements thereof without departing from the scope of the invention.In addition, many modifications may be made to adapt a particularsituation or material to the teachings of the invention withoutdeparting from the essential scope thereof. Therefore, it is intendedthat the invention not be limited to the particular embodiment disclosedas the best mode contemplated for carrying out this invention, but thatthe invention will include all embodiments falling within the scope ofthe claims. Also, in the drawings and the description, there have beendisclosed exemplary embodiments of the invention and, although specificterms may have been employed, they are unless otherwise stated used in ageneric and descriptive sense only and not for purposes of limitation,the scope of the invention therefore not being so limited.

1. A hydrostatic setting tool comprising; a housing defining a centralbore; a piston in the housing; a port in the housing exposed tohydrostatic pressure in use; a closure member preventing access of thehydrostatic pressure to the piston, the closure member being made atleast in part of an energetic degradable-on-demand material; and asource of energy connected to the closure member.
 2. The tool as claimedin claim 1 wherein the closure member is composed entirely ofdegradable-on-demand material.
 3. The tool as claimed in claim 1 whereinthe closure member includes seals at opposing ends, the closure memberbridging the port.
 4. The tool as claimed in claim 1 wherein the closuremember is oriented in parallel with the central bore.
 5. The tool asclaimed in claim 1 wherein the closure member bears a tensile load. 6.The tool as claimed in claim 1 wherein the closure member is arranged inparallel to the port and substantially perpendicular to the centralbore.
 7. The tool as claimed in claim 1 wherein the port is stepped. 8.The tool as claimed in claim 7 wherein the closure member contacts astop surface of the port.
 9. The tool as claimed in claim 1 wherein theclosure member extends into contact with a wall of the housingpreventing differential pressure based movement of the closure member.10. The tool as claimed in claim 1 wherein the tool further includes aretainer.
 11. A downhole system including the hydrostatic setting toolas claimed in claim
 1. 12. A method for setting a downhole toolcomprising: sending an electrical signal to a degradable-on-demandclosure member of a hydrostatic setting tool as claimed in claim 1;degrading the closure member; and providing access of hydrostaticpressure to the piston.
 13. The method as claimed in claim 12 whereinthe degrading is of the entirety of the closure member.
 14. The methodas claimed in claim 12 wherein the degrading is of a portion of theclosure member.
 15. (canceled)
 16. (canceled)
 17. The method as claimedin claim 12 wherein the degrading includes igniting of thedegradable-on-demand material.